Triangle Angle Sum and Exterior Angles Theorems

Front

What is the Triangle Angle Sum Theorem?

Back

The Triangle Angle Sum Theorem states that the sum of the interior angles of a triangle is always 180 degrees.

Front

What are remote interior angles in relation to an exterior angle?

Back

Remote interior angles are the two angles inside the triangle that are not adjacent to the exterior angle.

Front

If one angle of a triangle is 70 degrees, what is the sum of the other two angles?

Back

The sum of the other two angles is 110 degrees, since 180 - 70 = 110.

Front

What is the measure of an exterior angle of a triangle?

Back

An exterior angle of a triangle is equal to the sum of the two remote interior angles.

Front

If angle d is an exterior angle, which angles are its remote interior angles?

Back

The remote interior angles to angle d are the two angles inside the triangle that are not adjacent to angle d.

Front

What is the sum of the interior angles of a triangle?

Back

The sum of the interior angles of a triangle is 180 degrees.

Front

Solve for x if the angles of a triangle are x, 50, and 60 degrees.

Back

x = 70 degrees, since 50 + 60 + x = 180.

Front

If one angle of a triangle is 90 degrees, what can be said about the other two angles?

Back

The other two angles must sum to 90 degrees, making the triangle a right triangle.

Front

What is the relationship between an exterior angle and its adjacent interior angle?

Back

The exterior angle is equal to the sum of the two remote interior angles, not the adjacent interior angle.

Front

If angle a = 40 degrees and angle b = 60 degrees, what is angle c in triangle ABC?

Back

Angle c = 80 degrees, since 40 + 60 + c = 180.